Such bottom source air outlets are generally known and attempt to achieve a means for vertically introducing, with a low impulse, supply air through a floor into a space without turbulence. Depending on the presence of warm upward air current in the space or room, generated by people, lighting equipment, heat radiating devices and sunlight, the cold air that is supplied into the room through such source air outlets rises upwardly from the floor to the ceiling, where it is sucked out. When the rising air current of the room has a velocity of under 0.1 m/s, noticeable drafts are not present. However, effectively avoiding drafts is a problem.
Providing a horizontal air distribution of the air coming from such outlets poses another problem, because conventional air outlets of this type produce no appreciable horizontal penetration of air flows into the room. Therefore, it has been preferable to have linear air outlets that are arranged directly on the floor in front of railings or partitions. Linear air outlets supply the air into a room substantially horizontally at a velocity of about 0.20 m/s. The supply air flow spreads out over the floor and gradually rises upwardly. However, in such linear air outlets, the horizontal penetration of the air flows is still only about 6 meters at the most. Such a penetration range is not adequate to deliver supply air to all areas of wider or larger rooms.